package coq-core

  1. Overview
  2. Docs
package coq-core
Legend:
Page
Library
Module
Module type
Parameter
Class
Class type
Source

Source file eClause.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *         Copyright INRIA, CNRS and contributors             *)
(* <O___,, * (see version control and CREDITS file for authors & dates) *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

open CErrors
open Util
open Names
open Nameops
open Termops
open Constr
open Context
open Evarutil
open Tactypes

(** {6 Evar-based clauses} *)

type hole = {
  hole_evar : EConstr.constr;
  hole_type : EConstr.types;
  hole_deps  : bool;
  hole_name : Name.t;
}

type clause = {
  cl_holes : hole list;
  cl_concl : EConstr.types;
}

let qhyp_eq h1 h2 = match h1, h2 with
| NamedHyp n1, NamedHyp n2 -> lident_eq n1 n2
| AnonHyp i1, AnonHyp i2 -> Int.equal i1 i2
| _ -> false

let check_bindings bl =
  match List.duplicates qhyp_eq (List.map (fun {CAst.v=x} -> fst x) bl) with
    | NamedHyp s :: _ ->
        user_err ?loc:s.CAst.loc
          Pp.(str "The variable " ++ Id.print s.CAst.v ++
              str " occurs more than once in binding list.");
    | AnonHyp n :: _ ->
        user_err
          Pp.(str "The position " ++ int n ++
              str " occurs more than once in binding list.")
    | [] -> ()

let explain_no_such_bound_variable mvl {CAst.v=id;loc} =
  let open Pp in
  let expl = match mvl with
  | [] -> str "(no bound variables at all in the expression)."
  | [id] -> str "(possible name is: " ++ Id.print id ++ str ")."
  | _ -> str "(possible names are: " ++ pr_enum Id.print mvl ++ str ")."
  in
  user_err ?loc (str "No such bound variable " ++ Id.print id ++ spc () ++ expl)

let error_not_right_number_missing_arguments n =
  user_err
    Pp.(strbrk "Not the right number of missing arguments (expected " ++
        int n ++ str ").")

let make_evar_clause env sigma ?len t =
  let open EConstr in
  let open Vars in
  let bound = match len with
  | None -> -1
  | Some n -> assert (0 <= n); n
  in
  let rec clrec (sigma, holes) inst n t =
    if n = 0 then (sigma, holes, t)
    else match EConstr.kind sigma t with
    | Cast (t, _, _) -> clrec (sigma, holes) inst n t
    | Prod (na, t1, t2) ->
      (* Share the evar instances as we are living in the same context *)
      let inst, ctx, args, subst = match inst with
      | None ->
        (* Dummy type *)
        let hypnaming = RenameExistingBut (VarSet.variables (Global.env ())) in
        let ctx, _, args, subst = push_rel_context_to_named_context ~hypnaming env sigma mkProp in
        Some (ctx, args, subst), ctx, args, subst
      | Some (ctx, args, subst) -> inst, ctx, args, subst
      in
      let (sigma, ev) = new_pure_evar ~typeclass_candidate:false ctx sigma (csubst_subst sigma subst t1) in
      let ev = mkEvar (ev, args) in
      let dep = not (noccurn sigma 1 t2) in
      let hole = {
        hole_evar = ev;
        hole_type = t1;
        hole_deps = dep;
        (* We fix it later *)
        hole_name = na.binder_name;
      } in
      let t2 = subst1 ev t2 in
      clrec (sigma, hole :: holes) inst (pred n) t2
    | LetIn (na, b, _, t) -> clrec (sigma, holes) inst n (subst1 b t)
    | _ -> (sigma, holes, t)
  in
  let (sigma, holes, t) = clrec (sigma, []) None bound t in
  let holes = List.rev holes in
  let clause = { cl_concl = t; cl_holes = holes } in
  (sigma, clause)

let evar_with_name holes ({CAst.v=id} as lid) =
  let map h = match h.hole_name with
  | Anonymous -> None
  | Name id' -> if Id.equal id id' then Some h else None
  in
  let hole = List.map_filter map holes in
  match hole with
  | [] ->
    let fold h accu = match h.hole_name with
      | Anonymous -> accu
      | Name id -> id :: accu
    in
    let mvl = List.fold_right fold holes [] in
    explain_no_such_bound_variable mvl lid
  | h::_ -> h.hole_evar

let evar_of_binder holes = function
| NamedHyp s -> evar_with_name holes s
| AnonHyp n ->
  try
    let nondeps = List.filter (fun hole -> not hole.hole_deps) holes in
    let h = List.nth nondeps (pred n) in
    h.hole_evar
  with e when CErrors.noncritical e ->
    user_err Pp.(str "No such binder.")

let define_with_type sigma env ev c =
  let open EConstr in
  let t = Retyping.get_type_of env sigma ev in
  let ty = Retyping.get_type_of env sigma c in
  let j = Environ.make_judge c ty in
  let (sigma, j, _trace) = Coercion.inh_conv_coerce_to ~program_mode:false ~resolve_tc:true env sigma j t in
  let (ev, _) = destEvar sigma ev in
  let sigma = Evd.define ev j.Environ.uj_val sigma in
  sigma

let solve_evar_clause env sigma hyp_only clause = function
| NoBindings -> sigma
| ImplicitBindings largs ->
  let open EConstr in
  let fold holes h =
    if h.hole_deps then
      (* Some subsequent term uses the hole *)
      let (ev, _) = destEvar sigma h.hole_evar in
      let is_dep hole = occur_evar sigma ev hole.hole_type in
      let in_hyp = List.exists is_dep holes in
      let in_ccl = occur_evar sigma ev clause.cl_concl in
      let dep = if hyp_only then in_hyp && not in_ccl else in_hyp || in_ccl in
      let h = { h with hole_deps = dep } in
      h :: holes
    else
      (* The hole does not occur anywhere *)
      h :: holes
  in
  let holes = List.fold_left fold [] (List.rev clause.cl_holes) in
  let map h = if h.hole_deps then Some h.hole_evar else None in
  let evs = List.map_filter map holes in
  let len = List.length evs in
  if Int.equal len (List.length largs) then
    let fold sigma ev arg = define_with_type sigma env ev arg in
    let sigma = List.fold_left2 fold sigma evs largs in
    sigma
  else
    error_not_right_number_missing_arguments len
| ExplicitBindings lbind ->
  let () = check_bindings lbind in
  let fold sigma {CAst.v=(binder, c)} =
    let ev = evar_of_binder clause.cl_holes binder in
    define_with_type sigma env ev c
  in
  let sigma = List.fold_left fold sigma lbind in
  sigma
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct